AR# 50848

描述

If using the XAUI core v10.4 and earlier and RXAUI v2.3 and earlier with a 7 series FPGA, a reset might need to be issued after disabling loopback.

If you stop the far end (or valid data is not present on the RX serial data inputs), then put the core into loopback and bring it back out of loopback, a reset is required to correctly initialize the core.

解决方案

To work around this issue, you can either issue the main reset input to the core, or you can set the reset register bit to 0.15.